The thought for the week comes from Master Nagamines book,
The Essence of Okinawan Karate-Do.

On page 27, Master Nagamine states:
Kiai literally means spirit covergence or energy
concentration, taking advantage of a sound to fuse maximum
efficient force that can be exerted. When using kiai, one is using
the utmost life force.

At the center of the hara, (just below your bellybutton), the
meridians that carry life energy throughout your body converge.
Practice focusing that energy into and through your technique
as your breath is pushed out of your lungs by your diaphragm.